The present invention relates to apparatus for cooling or heating samples contained in the wells of well plates.
In pharmaceutical, genomic and proteomic research and drug development laboratories, and other biotechnology applications, automated liquid handlers are used for handling laboratory samples in a variety of laboratory procedures. For example, liquid handlers are used for biotechnological and pharmaceutical liquid assay procedures, sample preparation, compound distribution and the like. Sample containing plates having an array of many sample containing receptacles or wells are typically used. For example, one widely used sample containing well plate has an X-Y array of 96 deep wells in an eight by twelve well pattern. Other well plates having different arrays of sample wells are known. Typically the plates have a one piece molded plastic configuration with a peripheral skirt wall, an upper top wall and many individual sample containing wells spaced from adjacent wells and depending down from the top wall.
For some applications, it is desirable to maintain the samples in the sample containing wells at a reduced temperature or at an elevated temperature. Apparatus employing the peltier effect has been used to supply heat to or remove heat from samples in well plates. With the peltier effect heat is produced ort absorbed at the junction of two metals in response to the passage of electrical current. In known apparatus, a well plate is placed upon a heat conducing block or plate that is heated or cooled by one or more peltier effect modules. The well plate can be covered by a thermally insulating cover or can be placed beneath a second heat conducing block or plate that is heated or cooled by one or more peltier effect modules.
These known systems have been unable to effectively and consistently cool or heat samples in well plates. The plastic material of the well plate is not a good conductor of heat. As a result, heated or cooled plates or blocks at the top and/or bottom of the well plate are not in good thermal transfer relationship with samples in the plate wells. Heat is transferred primarily in vertical directions. Deep well plates have wells of about one and one half inches in depth, and this results in a large vertical distances between portions of a contained sample and a heat source or drain above or below the plate. If the well plate is highly insulated from ambient temperatures, known systems can eventually bring samples to or maintain a fairly consistent temperature, but due to the poor hear transfer, this requires substantial time. This is a serious disadvantage because delay prevents high procedure throughputs and can result in deterioration or alteration of the samples prepared for analysis.
A principal object of the present invention is to provide an improved apparatus for transferring heat to or from samples in wells of a well plate. Other objects are to provide a well plate heat transfer apparatus that can heat or cool sample wells with a high degree of uniformity and in a relatively short time; to provide a heat transfer apparatus that transfers heat to or from sample wells in lateral or horizontal rather than only vertical directions; and to provide a well plate heat transfer apparatus overcoming disadvantages of those used in the past.
In brief, in accordance with the invention there is provided heat transfer apparatus for well plates of the type having a plurality of vertically extending, spaced apart sample containing wells in an array with a predetermined pattern of spaces around the wells. The heat transfer apparatus includes a thermal transfer comb with a base panel and a plurality of vertically extending pins attached in heat transfer relationship to the base panel. The pins are arranged to correspond with the predetermined pattern of spaces around the wells of the well plate. A source for supplying or absorbing heat is in heat transfer proximity with the thermal transfer comb.